auto-type-checking

Auto Type Checking

Catch type errors immediately after every edit instead of discovering them at build time.

Manual Workflow

After editing a TypeScript file, run:

npx tsc --noEmit 2>&1 | head -30

If errors appear, fix them before moving on.

Automated with Cursor Hooks

Add to .cursor/hooks.json to run automatically after every file edit:

{
  "hooks": [
    {
      "event": "afterFileEdit",
      "script": "check-types.sh",
      "pattern": "**/*.{ts,tsx}"
    }
  ]
}

Create .cursor/hooks/check-types.sh:

#!/bin/bash
# Quick type check — only reports errors, doesn't block
npx tsc --noEmit --pretty 2>&1 | head -20
exit 0  # Don't block the agent even if there are errors

chmod +x .cursor/hooks/check-types.sh

What to Check

When type errors appear:

1. Missing imports: Cannot find name 'X' → add the import
2. Type mismatches: Type 'string' is not assignable to type 'number' → fix the type or the value
3. Missing properties: Property 'x' does not exist on type 'Y' → add the property to the interface or fix the access
4. Null safety: Object is possibly 'null' → add null check or optional chaining
5. Generic constraints: Type 'X' does not satisfy the constraint 'Y' → fix the generic parameter

Tips

• Use --noEmit to type-check without producing output files
• For large projects, tsc can be slow — consider --incremental or running only on changed files
• If using path aliases, ensure tsconfig.json paths are configured correctly
• For monorepos, run tsc from the package root, not the workspace root
• Pair with grinding-until-pass for a full "fix until clean" loop